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171.
Researchers have identified several problems in measuring the strongest path connecting pairs of actors in valued graphs. To address these problems, it has been proposed that average path value be used to indicate optimal connections between dyads. However, a lack of proper computer algorithm and its implementation has hindered a wide-range application of the proposed solution. In this paper we develop a computer algorithm and fully implement it with four JAVA programs, which are available on request. These programs produce an optimal connection matrix, which is subsequently inputted into UCINET for further multidimensional scaling and clustering analysis. We demonstrate this procedure with a data matrix containing 38 organizations in information technology. We discuss the methodological implications of the application of our algorithm to future social network studies. 相似文献
172.
测控数据实时监测软件是测控系统中的关键分系统之一,承担着大量测控信息的实时监视任务,由于其监测的数据具有信息量大、发送频率高、种类多样等特点,如何提升软件的性能和效率,成为了测控软件领域的一项重要课题。为实现该软件信息监测功能实时、全面、可靠,从软硬件平台、软件架构和算法设计等方面开展研究。采用多线程设计实现大量并行数据的接收,利用面向对象程序设计方法使数据处理层和展现层分离,对有曲线显示需求的数据存储方法进行了算法优化,从而实现软件的全面效能提升设计。设计的软件经实际环境测试,设计方法能够有效提升软件的效能,保证了测控数据监测功能的实时性和可靠性,增强了测控数据实时监测软件的数据承载能力。同时该方法设计的软件具有较好的可扩展性和可维护性。 相似文献
173.
针对遗传算法的有效性一般是通过数值实验来说明这一问题,本文在三个假设的条件下给出了一类混合遗传算法依概率收敛的证明,而且得到了在此算法的框架下通过改变子种群Ⅱ的变异算子而不改变依概率收敛特性的结论. 相似文献
174.
175.
带服务器的三台平行机排序问题的复杂性和近似算法 总被引:1,自引:0,他引:1
讨论带有两具服务器的三台机的平行机排序问题,在这个问题的实例中,每一个工件都有一个时间长度 安装操作必须要由服务器来完成,每一个服务器在同一时刻只能安装一个工件,用三段式描述表示此问题即为P3,S2/si=1/Cmax,证明了此问题为NP-C的,分别给出了在在线和离线条件下的近似算法,并且估计了算法的最坏情况界。 相似文献
176.
On the two-dimensional Knapsack Problem 总被引:1,自引:0,他引:1
We address the two-dimensional Knapsack Problem (2KP), aimed at packing a maximum-profit subset of rectangles selected from a given set into another rectangle. We consider the natural relaxation of 2KP given by the one-dimensional KP with item weights equal to the rectangle areas, proving the worst-case performance of the associated upper bound, and present and compare computationally four exact algorithms based on the above relaxation, showing their effectiveness. 相似文献
177.
In this paper, we address an optimization problem that arises in the context of cache placement in sensor networks. In particular, we consider the cache placement problem where the goal is to determine a set of nodes in the network to cache/store the given data item, such that the overall communication cost incurred in accessing the item is minimized, under the constraint that the total communication cost in updating the selected caches is less than a given constant. In our network model, there is a single server (containing the original copy of the data item) and multiple client nodes (that wish to access the data item). For various settings of the problem, we design optimal, near-optimal, heuristic-based, and distributed algorithms, and evaluate their performance through simulations on randomly generated sensor networks. 相似文献
178.
Privacy-preserving data publishing (PPDP) deals with data publishing while preserving individual's privacy in the data. Recent researches show that knowledge of mechanism of anonymization provides a loophole for attacks [1], [2], we call this kind of attack a mechanism-based attack. In this paper, we first give a comprehensive study of mechanism-based attack and point out that the range of mechanism-based disclosure is much broader than ever said. Then, we analyze the rationale of mechanism-based attack and give the definition of mechanism-based attack formally. To counteract mechanism-based attack, we introduce a model called e-secrecy and corresponding solution algorithm MAIA. We conduct a comprehensive set of experiments to show mechanism-based attacks are practical concern in the real-world data sets and that our method introduces better data utility and very minor computation than the existing algorithms. 相似文献
179.
180.
Mohammadreza Khanmohammadi 《光谱学快报》2013,46(4):269-272
An accurate and stable algorithm, QR Decomposition Algorithm (QRDA) is initially presented into the chemistry field. The basic principle of QR Multivariate Calibration Algorithm (QRMCA) is investigated, and the complexes system of sodium tripolyphosphate (STPP), sodium sulfate (SS), and sodium Carbonate (SC) with serious overlapping absorption peaks is analyzed by QRMCA. According to our survey, QRDA can avoid matrix inverting, reduce the orders of matrixes, and speed up the operation of matrices. So, it has bright prospects in chemometrics. The process of the QR Decomposition Algorithm (QRDA) was implemented by an orthogonal and upper triangular matrix decomposition that is robust and convenient. Then it was applied to overcome the problem of overlapping spectra of different components in detergent-washing powder. 相似文献